The company, whose sole director David Gill founded the zoo, entered guilty pleas at Preston Crown Court on Wednesday to contravening health and safety laws on the day of the tragedy.

The company was fined an additional £42,500 after it had also pleaded guilty to other health and safety law breaches when a zoo keeper fell from a ladder while preparing to feed big cats on July 18 2014.

It must also pay £150,000 prosecution costs.

Sentencing, Mr Justice Turner said "it should not have been possible" for the tiger to gain access to where Miss McClay was working.

He said: "But as a substantially contributory cause as a result of a door-closing mechanism failure, it did.

"The result was as tragic as it was foreseeable. The tiger attacked and Sarah was fatally injured."

The judge said the incident the following year involving a ladder was "an accident waiting to happen".

South Lakes Safari Zoo Ltd admitted that on or before May 24 2013, it failed to ensure the health, safety and welfare at work of employees - including Miss McClay - arising out of and/or in connection with the keeping of big cats.

It also pleaded guilty to failing to ensure that persons not in its employment on the above date were not exposed to risk to their health and safety.

The pleas came ahead of a scheduled trial, and the prosecution offered no evidence against Mr Gill 55 - who had faced individual charges on the same allegations.

Miss McClay suffered "unsurvivable" multiple injuries and was airlifted from the scene to hospital where she was formally pronounced dead.

In September 2014, an inquest jury in Kendal ruled in a narrative verdict that Padang the Sumatran tiger got to Miss McClay by entering two open internal sliding gates within the tiger house and then an open door from the tiger's "dark den" that led on to the corridor.

Systems were in place at the park to ensure that animals and keepers remained apart at all times through indoor and outdoor compartments connected by lockable self-closing doors.

The animal was supposed to never have access to the corridor, but the male tiger walked through the dark den door to where Miss McClay, from Barrow-in-Furness, was carrying out cleaning and feeding duties in the house.

Two internal sliding gates were also open, which allowed Padang and his female companion, Alisha, to move in and out of a light den and a dark den to the outside enclosure.

The company accepted its risk assessment did not address sufficiently the risks arising from a failure to maintain the dark den door - labelled in court as "the last line of defence" for the animal keepers.

The company said "a more proactive maintenance and inspection regime" should have been in place to ensure that the door functioned efficiently and that its self-closing mechanism worked properly.